docs: def on_connection_open(self, connection):
          """This method is called by pika once the connection to RabbitMQ has
          been established.
  
          :type connection: pika.TornadoConnection
  
          """
          LOGGER.debug('Connection opened')
          connection.add_on_connection_blocked_callback(
              self.on_connection_blocked)
          connection.add_on_connection_unblocked_callback(
              self.on_connection_unblocked)
          connection.add_backpressure_callback(self.on_back_pressure_detected)
          self.channel = self._open_channel()